TSH levels in pregnant women with iodine deficiency before spontaneous abortus

Abstract

Background: Iodine deficiency and/or thyroid autoimmunity are the most common causes of hypothyroidism development among pregnant women. In this study, we aimed to investigate the effect of iodine consumption and thyroid autoimmunity on TSH levels and abortus.The study sample consisted of 104 patients, 79 in abortus and 25 in control groups. TSH, free T4, free T3, anti-TPO, anti-Tg, spot urinary iodine concentrations, and thyroid volumes of the cases were measured by ultrasonography.The spot urine concentration was below 100 µg/L in 93% of the cases included in the study. The TSH levels of the abortus group cases were significantly higher than those of the controls (p=0.025). The percentage of subclinical hypothyroid cases were significantly higher among the cases evaluated due to abortus compared to the control group (p< 0.001). Abortus and control groups did not differ statistically with respect to the presence of autoimmune thyroid diseases (p=0.424). Spot urine iodine concentrations of abortus cases with subclinical hypothyroid were significantly lower than those with TSH levels below the defined range (p=0.001). Spot urine iodine concentrations of the cases with subclinical abortus with negative thyroid autoantibodies were also significantly lower than those with TSH levels below the defined range (p=0.017).TSH levels above 1 µIU/mL for the first trimester and 2 µIU/mL for the second trimester may be indicators of iodine nutrition in pregnancy losses.